The fast thermal stopped-flow apparatus has been further tested and improved. A pressure artifact has been ascertain to be due to the Adiabatic compressability of water. The effect is reduced, interestingly enough, in the presence of albumin. The reaction of CO2 with glycylglycine has been carried out and the delta H and rate constant agree with the literature value. By correcting the data for the amine ionization the heat of binding is found to be 5.5 Kcal/mole at 25 degrees C. A 1 microsecond response time dual wavelength detector system has been built and tested for use with whole blood in the laser flash photolysis apparatus. 660 and 900 nm LED'S and EG/G HAD 1000 detectors are used. A 5 microns time is presently the response limit due to the laser photolysis artifact.